Cooling structure, electronic apparatus, cooling system, and method for cooling electronic element

Abstract

The present invention provides a cooling structure, an electronic apparatus, a cooling system, and a method for cooling an electronic element whereby the normal operating time of an electronic apparatus can be extended. A cooling structure 50 for cooling an electronic element 11 that performs electronic processing comprises: a cooling liquid 12 for cooling the electronic element 11, the cooling liquid 12 being water that has been transitioned from a state at a temperature exceeding a critical temperature and a pressure exceeding a critical pressure to a state at a normal temperature and a normal pressure; and a misting unit 51 that generates a cooling mist MST obtained by misting the cooling liquid 12.

Description

Cooling Structure, Electronic Device, Cooling System, and Method for Cooling Electronic Components

[0001] The present invention relates to a cooling structure, an electronic device, a cooling system, and a method for cooling electronic components.

[0002] For the purpose of effectively cooling an electronic component provided in an electronic device, a technique for cooling the electronic component by immersing water in a coolant is disclosed in Patent Document 1. The coolant serves as a refrigerant.

[0003] Japanese Unexamined Patent Application Publication No. 2019 - 145749

[0004] Some electronic devices have a structure in which the terminals of electronic components are detachably attached to a circuit board or the like. In addition, some electronic devices have a structure in which the terminals of electronic components are brazed to a circuit board. However, when an electronic device has a structure different from the brazing structure as the connection structure between the terminals of electronic components and the circuit board, there are the following problems when water is used as the coolant. That is, when water is used as the coolant in such an electronic device, the normal operating time of the electronic device may be shorter than when the electronic device has a brazing structure.

[0005] Therefore, even when water is contained in the coolant, an improvement has been demanded from the viewpoint of making it possible to extend the normal operating time of the electronic device when cooling the electronic component.

[0006] One object of the present invention is to provide a cooling structure, a cooling system, and a method for cooling electronic components that can extend the normal operating time of an electronic device.

[0007] The present invention is summarized in the following (1) to (6): (1) A cooling structure for cooling an electronic element that performs electronic processing, comprising: a cooling liquid for cooling the electronic element, which is water that has been transitioned from a state under a temperature and pressure exceeding a critical temperature and pressure to a state under normal temperature and normal pressure; and a misting unit that generates a cooling mist by atomizing the cooling liquid. (2) The cooling structure according to (1) above, wherein at least a portion of the cooling mist is configured to come into contact with the electronic element. (3) The cooling structure according to (2) above, further comprising a blower unit that forms an airflow. (4) An electronic device comprising the cooling structure according to any one of (1) to (3) above, and the electronic element that performs electronic processing. (5) A cooling system for cooling an electronic element that performs electronic processing, comprising: a cooling chamber having a space for arranging the electronic element; a cooling liquid for cooling the electronic element, which is water that has been transitioned from a state under a temperature and pressure exceeding a critical temperature to a state under normal temperature and normal pressure; and a misting unit that generates a cooling mist by atomizing the cooling liquid. (6) A method for cooling an electronic element that performs electronic processing, comprising cooling the electronic element with a cooling mist obtained by atomizing the cooling liquid, wherein the cooling liquid is water that has been transitioned from a state under a temperature and pressure exceeding a critical temperature to a state under normal temperature and normal pressure.

[0008] The present invention may also be the inventions described in (7) to (8) below. (7) A cooling system according to (5) above, wherein at least a portion of the cooling mist is configured to come into contact with the electronic element. (8) A cooling system according to (5) above, comprising a blower that forms an airflow, wherein the gas in contact with the surface of the cooling mist that comes into contact with the electronic element moves in accordance with the airflow formed by the blower.

[0009] According to the present invention, it is possible to provide a cooling structure, an electronic device, a cooling system, and a method for cooling electronic elements that can extend the normal operating time of an electronic device.

[0010] Figure 1A is a configuration diagram illustrating one embodiment of a first example of an electronic device equipped with a cooling structure. Figures 1B and 1C are cross-sectional views illustrating a structure for connecting electronic elements to a circuit board. Figure 2 is a block diagram illustrating the configuration of an electronic device. Figure 3 is a diagram illustrating a method for producing supercritical water. Figure 4 is a configuration diagram illustrating one embodiment of the configuration of an electronic device equipped with a cooling structure. Figure 5 is a diagram illustrating one embodiment of a second example of an electronic device. Figure 6 is a configuration diagram illustrating one embodiment of a cooling system. Figure 7 is a flowchart illustrating one embodiment of a method for cooling electronic elements.

[0011] Embodiments of the present invention will be described in order as follows: 1. Cooling structure, 2. Cooling system, and 3. Cooling method. In this specification, the electronic device will be described in conjunction with the description of the cooling structure.

[0012] However, the present invention is not limited to the embodiments described below.

[0013] [1. Cooling Structure] The cooling structure according to the present invention is a structure for cooling an electronic element that performs electronic processing. In this specification, the description of the cooling structure will continue with the example of a case in which the cooling structure is provided in an electronic device, as shown in Figure 1. Figure 1 is a configuration diagram for illustrating one embodiment (first example) in which the cooling structure is provided in an electronic device. Figure 1 shows one embodiment in which the electronic device is an information processing device such as a computer. In Figure 1, the Z-axis direction is defined as the vertical direction, the side with the arrow +Z direction is the upper side, and the side with the arrow -Z direction is the lower side. This is also the case for Figures 4, 5 and 6.

[0014] [1-1. Electronic Devices Having a Cooling Structure] [1-1-1. First Example] The electronic device 10 (10A) shown in the example of Figure 1 includes an electronic element 11. As shown in the example of Figure 1, the electronic device 10 includes a cooling structure 50 for cooling the electronic element 11. The electronic device 10A shown in Figure 1 is an embodiment of the first example of an electronic device having a cooling structure. Furthermore, the first example of an electronic device having a cooling structure may be referred to as the first example of an electronic device.

[0015] (Electronic Devices) Examples of electronic devices to which the cooling structure according to the present invention can be provided include devices that may generate heat during operation. For example, examples of electronic devices include computers, supercomputers, quantum computers, inverters, converters, motor drive devices, communication devices (e.g., 5G and 6G), control devices for robots (power devices), transformers, etc. The above-mentioned 5G is 5th Generation Mobile Communication System. The above-mentioned 6G is 6th Generation Mobile Communication System.

[0016] (Electronic Elements) Electronic elements 11 are elements that perform electronic processing. Examples of electronic elements 11 include, for example, a chipset made of semiconductor elements. The type of electronic element 11 is not particularly limited. Examples of electronic elements 11 include those that may generate heat due to various conditions such as the exchange of electrical signals, or those whose function may be impaired by heat. Examples of those whose function may be impaired by heat include elements with weaker heat resistance compared to the "other elements" described later. Specifically, examples of electronic elements 11 include information processing elements, memory elements, and power elements. Examples of information processing elements include arithmetic elements, control elements, CPUs (Central Processing Units), GPUs (Graphics Processing Units), MPUs (Micro-Processing Units), etc. Examples of memory elements include non-volatile memory such as flash memory, and volatile memory such as RAM. A power device is a power semiconductor, or a device containing a power semiconductor. A power semiconductor is a semiconductor that can handle high voltages and large currents. Generally, power semiconductors have a different structure from ordinary semiconductors so that they do not break down even when subjected to high voltages and / or large currents. Because such power semiconductors handle large amounts of power, they are known to generate heat and become hot.

[0017] The various electronic elements 11 described above may be selected according to various conditions such as the function of the electronic device 10. For example, in the example of Figure 2, the electronic device 10 has a CPU 11A, a GPU 11B, a memory 11C, etc., as electronic elements 11. The CPU 11A, GPU 11B, and memory 11C are electrically connected. Figure 2 is a configuration diagram illustrating an example of the configuration of the main electronic elements 11 in the example of the electronic device 10 shown in Figure 1A. In the example of the electronic device 10 shown in Figure 2, the GPU 11B and memory 11C are connected to the CPU 11A so as to be able to transmit electrical signals. The CPU 11A is connected to the I / O port 40 so as to be able to transmit electrical signals. In the example of Figure 2, the I / O port 40 is configured to transmit signals to other devices. For example, in the example of Figure 1A, an external connection terminal 13 is provided as the I / O port 40. Figure 2 illustrates the case where the external connection terminal 13 is connected to an external device 14. In the example shown in Figure 1A, the connection portion 23 is formed by connecting the external connection terminal 13 to the connection terminal 41 of the external device 14. In Figure 2, for the sake of explanation, only signal lines are shown in the wiring. Also, in Figure 2, other structures and devices electrically connected to the electronic element 11 via signal lines, power supply and power lines are omitted. Other devices electrically connected to the electronic element 11 via signal lines can be exemplified by devices such as the external device 14. Note that the example shown in Figure 2 is just one example of the configuration of the electronic element 11. The configuration shown in Figure 2 is not limited to the type of electronic element 11, the layout, or the interconnection state of the electronic elements 11. Furthermore, the device connected via the I / O port 40 may or may not be included in the electronic device 10. Examples of devices connected via the I / O port 40 include the external device 14.

[0018] The electronic device 10 has a circuit board 15. As shown in Figure 1A, electronic elements 11 are provided on the circuit board 15. The electronic elements 11 are electrically connected to wiring 16 formed on the circuit board 15. In the example in Figure 1A, a CPU 11A, a GPU 11B, and a memory 11C, which are examples of electronic elements 11, are mounted in predetermined positions on the circuit board 15. In Figure 1, for the sake of explanation, only a portion of the wiring 16 is shown, and the description of other wiring is omitted. The same applies to Figures 4 and 6.

[0019] (Circuit board) The circuit board 15 has a board body 17 and wiring 16. The wiring 16 is electrically connected to the terminals 18 of the electronic element 11. The electronic device 10 has an element connection portion 19 as the connection point between the wiring 16 and the terminals 18 of the electronic element 11.

[0020] The method for forming the element junction 19 is not particularly limited. Preferably, the element junction 19 is formed by joining the wiring 16 and the terminal 18 of the electronic element 11 using metal. In other words, it is preferable that a joining method using metal is employed for forming the element junction 19.

[0021] Examples of methods that can be used to form the element junction 19, and that use metal, include joining by metal fusion and crimping. Examples of joining by metal fusion include soldering and wire bonding (not shown). The structure shown in Figure 1B, in which the wiring 16 and the terminal 18 of the electronic element 11 are joined with solder 30, is an example of a structure using the soldering method. An example of crimping is a method in which the wiring 16 and the terminal 18 of the electronic element 11 are directly joined (metal joining). Furthermore, the element junction 19 may be formed by methods other than those described above. For example, a receiving portion 31 corresponding to the shape of the terminal 18 of the electronic element 11 may be formed on the wiring 16 on the circuit board 15. Then, as shown in Figure 1C, the terminal 18 is fitted into the receiving portion 31 formed on the wiring 16. The element junction 19 may be formed in this way. The cooling structure 50 of the present invention can be expected to be particularly effective when, as shown in Figure 1C, an element junction 19 is formed by fitting a terminal 18 into a receiving portion 31 formed by wiring 16. However, this is not limited to the case where the element junction 19 is formed by fitting a terminal 18 into a receiving portion 31 as shown in Figure 1C.

[0022] The material of the substrate body 17 is not particularly limited. Examples of materials for the substrate body 17 include glass epoxy substrates, bakelite substrates, fluororesin substrates, flexible substrates using PET film, etc. The material of the wiring 16 is not particularly limited as long as it is a metal on which circuits can be formed on the substrate body 17. The material of the wiring 16 may be at least one selected from the group consisting of copper, silver, gold, and aluminum. When the wiring 16 and the terminals 18 of the electronic element 11 are connected by wire bonding using a wire, the material of the wire is not particularly limited. Examples of wire materials include metals that can be used as the material for the wiring 16 as described above (for example, gold, etc.).

[0023] In the example shown in Figure 1A, various electronic elements 11 are mounted on a single circuit board 15, and external connection terminals 13 are also attached. Examples of the various electronic elements 11 include semiconductor chipsets and / or memory 11C, etc. Examples of semiconductor chipsets include a CPU 11A and a GPU 11B. The electronic device 10 may also have other electronic elements 11 besides the CPU 11A and GPU 11B, such as additional semiconductor chipsets. The functions of the additionally added chipsets may be determined according to various conditions such as the functions of the electronic device 10.

[0024] (Configuration of the cooling structure) The electronic device 10 is provided with a cooling structure 50 as described above. The cooling structure 50 comprises a cooling liquid 12 and a misting unit 51.

[0025] (Misting Unit) The misting unit is a structural unit that generates cooling mist (MST) by atomizing the coolant. The structure of the misting unit is not particularly limited. For example, the structure of the misting unit is one that atomizes the coolant using ultrasound. However, this is just one example of a misting unit. For example, the structure of the misting unit can be a nozzle type. For example, a nozzle type structure can be shown in which a coolant pressurized to high pressure (for example, about 7 MPa) is pushed out into a low-pressure area from a mist nozzle with a small diameter. The mist nozzle of the sprayer may be a one-fluid nozzle or a two-fluid nozzle. An example of a two-fluid nozzle is a nozzle that mixes with air using the Venturi effect.

[0026] In the example shown in Figure 1A, the coolant 12 is stored inside the atomizing section 51 of the electronic device 10. However, this is just one example. The electronic device 10 may also be provided with a tank separate from the atomizing section 51. This tank, separate from the atomizing section 51, may be configured to store the coolant and may also be configured to supply the coolant from the tank to the atomizing section (not shown). Alternatively, the coolant may be prepared separately from the electronic device 10. In this case, the electronic device 10 may be configured so that the prepared coolant is supplied to the atomizing section 51 from outside the electronic device 10 (not shown).

[0027] In the cooling structure, it is preferable that at least a portion of the cooling mist is configured to come into contact with the electronic element. This configuration means that at least one of the numerous liquid particles constituting the cooling mist comes into contact with the electronic element. As will be described later, since the cooling liquid constituting the cooling mist is supercritical water, it absorbs heat from its surroundings when it vaporizes. The contact of the cooling mist with the electronic element allows for more reliable cooling of the electronic element when the cooling mist vaporizes.

[0028] The particle size of the cooling mist (MST) is not particularly limited as long as it is small enough to be carried by the airflow. For example, if the atomizing unit has a structure that atomizes the cooling liquid using ultrasound, the atomizing unit can prepare cooling mist MST with a particle size of approximately 3 μm to 10 μm. If the atomizing unit has a nozzle-type structure, the atomizing unit can prepare cooling mist MST with a particle size of approximately 10 μm to 100 μm. Note that the particle sizes of the cooling mist MST shown here are just examples, and if the atomizing unit has a structure that realizes mist spraying using the Venturi effect, the particle size can be approximately 150 nm to 400 nm.

[0029] From the viewpoint of facilitating the cooling of electronic components by contact between the cooling mist and the electronic components, it is preferable that the temperature of the cooling mist MST be as low as possible. From the viewpoint of enhancing the cooling effect of the cooling mist, the cooling mist MST may be made into a liquid mist in the atomization section and then further cooled into a dust-like solid.

[0030] (Other forms of coolant) According to the cooling structure of the present invention, it is sufficient that at least a portion of the coolant 12 is atomized into a cooling mist MST. A portion of the coolant 12 does not need to be atomized. For example, a portion of the coolant 12 may be applied to the electronic element 11 in the form of a continuous liquid shower. A continuous liquid shower can be achieved, for example, by spraying a portion of the coolant 12 with a sprinkler. The cooling mist MST and the continuous liquid shower may be sprayed separately or mixed together. From the viewpoint of cooling stability and driving stability of the electronic element 11, it is preferable that the entire coolant 12 is atomized into a cooling mist MST.

[0031] (Coolant) The coolant 12 is a liquid for cooling the electronic elements 11. Specifically, the coolant 12 is supercritical water 21. The coolant 12 is not prohibited from being a liquid that contains other components in addition to supercritical water 21, to the extent that it does not affect the operation of the electronic elements 11 and circuit board 15 that are cooled by it. From the viewpoint of cooling stability, it is more preferable that the coolant 12 is a liquid in which the addition of other components to supercritical water 21 is avoided.

[0032] (Supercritical Water) In this specification, supercritical water 21 refers to (is defined as) water that has undergone a transition from a supercritical state to a state at room temperature and atmospheric pressure. A supercritical state refers to a state at a temperature and pressure exceeding the critical temperature and critical pressure. The combination of critical temperature and critical pressure is sometimes called the critical condition. The term supercritical water is a name established for the convenience of explanation to refer to water in the above state (a name referring to water specified in the above definition). Water corresponding to supercritical water may be referred to by different names. For example, if the definition is the same, supercritical water may be referred to as water that has passed through the critical point, etc. In this specification, room temperature refers to, for example, a temperature of about 1°C to 35°C. Atmospheric pressure refers to, for example, a pressure of about 1 atm (about 0.1013 MPa). Room temperature may be the room temperature in the human living area. Atmospheric pressure may be the atmospheric pressure in the human living area. It is preferable that the supercritical water 21 has as few mineral components as possible removed. Therefore, it is preferable that the supercritical water 21 is water from which mineral components (including ionic components) have been removed by ion exchange treatment or the like, as described later. Examples of mineral components include metals, halogens, and salts containing these elements. Examples of metals include sodium, calcium, and magnesium. Examples of halogens include chlorine. Examples of salts containing these elements include salts containing sodium, calcium, and / or magnesium, as well as chlorine, as mentioned above. Furthermore, examples of ionic components that are preferable to be removed in the supercritical water 21 include various metal ions and halide ions. Examples of various metal ions include alkali metal ions such as sodium ions, and alkaline earth metal ions such as calcium ions and magnesium ions. Examples of halide ions include chloride ions.

[0033] (Supercritical Water Production Apparatus and Method) Supercritical water 21 can be produced, for example, using an apparatus as shown in Figure 3. Figure 3 is a diagram showing an example of an apparatus for producing supercritical water 21. The following explanation using Figure 3 is an example. The apparatus and method for producing supercritical water 21 are not limited to the example described herein.

[0034] The apparatus for producing supercritical water 21 illustrated in Figure 3 comprises a pressurizing unit 100 and a heating unit 110. The apparatus for producing supercritical water 21 is provided with piping 120 connecting the pressurizing unit 100 and the heating unit 110. The pressurizing unit 100 can be, for example, a pressurizing device such as a high-pressure pump. The heating unit 110 can be, for example, a known heating heater.

[0035] In the manufacturing apparatus shown in Figure 3, the raw material water is injected into the pressurization unit 100. The raw material water is sometimes referred to as raw water. In Figure 3, the raw water is indicated by the symbol W (in). The raw water is raised in the pressurization unit 100 to a pressure exceeding the critical pressure of water (approximately 22 MPa). The temperature inside the pressurization unit 100 is set to a temperature at which solidification of the raw water is restricted. Next, the fluid pressurized in the pressurization unit 100 is sent from the piping 120 to the heating unit 110. In the heating unit 110, the fluid is heated to a temperature exceeding the critical temperature of water (approximately 374°C). At this time, the fluid inside the heating unit 110 is in a state of temperature and pressure exceeding the critical conditions for water (pressure: approximately 22 MPa, temperature: approximately 374°C), i.e., it is in a supercritical state. After being heated in the heating unit 110, the temperature and pressure of the fluid inside the heating unit 110 are reduced to room temperature and atmospheric pressure. As a result, the fluid transitions to a state under normal temperature and pressure, i.e., to a state of water. Subsequently, the fluid that flows out from inside the heating section 110 to the outside becomes supercritical water 21. The fluid that flows out from inside the heating section 110 to the outside is indicated by the symbol W (out) in Figure 3. Note that the process of lowering the temperature and pressure of the heating section 110 to normal temperature and pressure can be achieved, for example, by providing a cooling device and a depressurization device in the heating section 110.

[0036] The raw water used in producing supercritical water 21 is not particularly limited. Examples of raw water include tap water, mineral water, and pure water. It is preferable that the raw water be pure water, as impurities have been removed as much as possible. In particular, from the viewpoint of preventing the supercritical water 21 from containing mineral components, it is preferable that the raw water has had mineral components removed as impurities. Therefore, it is preferable that the raw water is water from which mineral components have been removed by ion exchange treatment or the like. However, this does not prohibit the use of raw water that contains mineral components. In this case, for example, after producing supercritical water 21 using water containing mineral components and the production apparatus shown in Figure 3, the mineral components may be removed from the supercritical water 21. Examples of mineral component removal include ion exchange treatment. By removing mineral components from the supercritical water 21, it is possible to obtain an effect of preventing rust caused by the adhesion of salts to the surface of the misting section and electronic elements. Furthermore, because mineral components are removed from the supercritical water 21, it is possible to prevent scale from adhering to the surface of the misting section 51 and the electronic elements 11.

[0037] The pressurization mechanism of the pressurization unit 100 is not particularly limited as long as it can pressurize the water to a pressure above critical pressure. For example, in addition to pressurization by a high-pressure pump, the pressurization mechanism of the pressurization unit 100 may employ the following mechanism. That is, a mechanism that fills a continuous pipe from a high place to a low place with raw water to raise the water level of the raw water to a high place is also possible. In such a mechanism, a state is created in which the hydrostatic pressure at the low place is increased. As a result, the raw water located at the low place is pressurized. The high place where the critical pressure of water is achieved should be at a height of approximately 2200m or more relative to the low place.

[0038] The heating mechanism of the heating section 110 is not particularly limited as long as it can raise the temperature to a temperature exceeding the critical temperature of water. Examples of heating mechanisms for the heating section 110 include mechanisms that utilize the heat of combustion of organic matter, mechanisms that utilize light energy such as sunlight, and / or mechanisms that utilize heat generated by the passage of electricity such as electric heating wires.

[0039] In the above manufacturing apparatus, the pressure boosting unit 100 and the heating unit 110 are connected by piping 120, and pressure boosting and heating are performed separately. However, the heating unit 110 may be provided within the pressure boosting unit 100, so that pressure boosting and heating can be performed simultaneously.

[0040] (Other elements and other substrates) The electronic device 10 may have "other elements" in addition to the electronic elements 11 described above. Examples of other elements include elements that do not require cooling. Examples of other elements include capacitors, resistors, and / or coils (inductances). It is preferable that the elements 22 that do not require cooling are placed in a position where cooling mist is unlikely to reach them. This is just one example. The arrangement of elements 22 in the electronic device 10 is not limited to the arrangement described above.

[0041] [1-1-2. Function and Effects] To avoid deterioration or destruction of electronic devices due to heat generation from electronic components during operation, technologies for cooling electronic components have been proposed. One proposed technology for cooling electronic components is immersion in a coolant. In addition, the use of water as the coolant has been proposed.

[0042] Some electronic devices have a structure in which the terminals of electronic elements are detachably attached to a circuit board or the like. Other electronic devices have a structure in which the terminals of electronic components are brazed to a circuit board. An example of a structure in which the terminals of electronic elements are detachably attached to a circuit board or the like is the structure shown in Figure 1C. An example of a structure in which the terminals of electronic components are brazed to a circuit board is the structure shown in Figure 1B. In electronic devices that do not employ a brazed structure, water may seep between the terminals of the electronic components and the connection terminals of the circuit board over time. In this case, the electrical connectivity between the electronic elements and the circuit board in the electronic device may be affected. Therefore, the time during which the electronic device operates normally may be shortened. Accordingly, when immersing electronic elements in a liquid such as a coolant, it is important to carefully consider the possibility of affecting the electrical connectivity between the electronic elements and the connection terminals of the circuit board. When electronic elements are immersed in a liquid such as a coolant, this is sometimes referred to as immersion immersion.

[0043] According to the cooling structure of the present invention, a cooling mist MST in which the coolant 12 is atomized is used for cooling an electronic element. Therefore, according to the cooling structure of the present invention, the cooling effect of the electronic element due to contact with the cooling mist and the cooling effect of the electronic element due to heat absorption during vaporization of the cooling mist can be expected. Further, the coolant is in an atomized state. Therefore, it is more difficult for the coolant to enter the gap between the terminal of the electronic element and the connection terminal of the circuit board than in the case of liquid immersion. And the contact state between the terminals is likely to be kept in a good state, and the time during which the electronic device operates normally becomes longer. Furthermore, when using a cooling mist in which the coolant is atomized, even if the coolant enters the gap between the terminal of the electronic element and the connection terminal of the circuit board, the coolant in the state of the cooling mist is likely to vaporize before affecting the operation of the electronic device. Therefore, compared with the case where the electronic element is immersed in the coolant, when using a cooling mist in which the coolant is atomized, it is possible to eliminate the state where the coolant has entered the gap between the terminal of the electronic element and the connection terminal of the circuit board in a relatively short time. And from this, according to the cooling structure of the present invention, the time during which the electronic device operates normally becomes longer.

[0044] When an electronic device or an electronic element is cooled by a coolant by liquid immersion, it is important to replace the coolant in consideration of the possibility that the coolant may be contaminated by the use of the coolant. According to the cooling structure of the present invention, an electronic device having an electronic element or the electronic element is cooled by a cooling mist. Therefore, the necessity of replacing the coolant such as liquid immersion can be suppressed. Specifically, for example, the operation of replacing the coolant can be omitted.

[0045] Furthermore, according to the cooling structure of the present invention, the coolant 12 is composed of supercritical water 21. Therefore, according to the cooling structure of the present invention, compared to cases where the coolant 12 is not composed of supercritical water 21, even if mist adheres to the electronic element being cooled and / or the mist turns into water droplets and adheres to the electronic element, wetting the electronic element has less impact on the operation of the electronic device. And because even if the coolant 12 turns into water droplets and adheres to the electronic element, wetting the electronic element has less impact on the operation of the electronic device, it becomes easier to control the generation of cooling mist and temperature, etc.

[0046] Furthermore, the cooling structure according to the present invention enables effective cooling of electronic devices and electronic components with electronic elements using a simple configuration that only requires a structure for atomizing supercritical water. Examples of the structure for atomizing supercritical water include a sprayer. The structure for atomizing supercritical water can be constructed more simply than when electronic devices and electronic components with electronic elements are cooled by immersion using supercritical water as a coolant. Therefore, the cooling structure according to the present invention enables low-cost cooling of electronic devices and electronic components.

[0047] [1-1-3. Modified Examples] As shown in Figure 4, the cooling structure may have an air blower. When the cooling structure has an air blower in this way, it will be referred to as the modified cooling structure. Figure 4 is a diagram illustrating the modified cooling structure. Figure 4 shows a configuration diagram illustrating one embodiment of an electronic device in which the electronic device has an example of the modified cooling structure. In the example shown in Figure 4, an example is provided in which the modified cooling structure is provided in the first example of the electronic device 10. The modified cooling structure will be explained with reference to Figure 4.

[0048] In the electronic device 10 (10B) shown in FIG. 4, for other components (components such as electronic elements and circuit boards) excluding the cooling structure, all of the above descriptions (the descriptions shown in the above [1-1-1. First Example] and the above "1-1-2. Operations and Effects") can be applied. For the cooling structure, for other components (cooling liquid, misting unit, etc.) excluding the blower unit described later, all of the above descriptions can be applied.

[0049] (Blower Unit) The blower unit forms an air current. In the example of FIG. 4, a cooling fan 32 is provided as the blower unit. Examples of the cooling fan 32 include an axial fan, a centrifugal fan, a blower, etc. In the cooling fan 32 shown in the example of FIG. 4, the direction in which the air flows is from the inside to the outside of the electronic device. However, this is just an example. In the cooling structure of the present invention shown in a modification example of an electronic device equipped with a cooling structure, it is not prohibited that the direction in which the air flows formed by the cooling fan 32 is from the outside to the inside of the electronic device. Also, a plurality of cooling fans 32 may be provided. In this case, the cooling fans 32 may be provided for each electronic element 11.

[0050] In a modification example of an electronic device equipped with a cooling structure according to a modification example, when at least a part of the cooling mist MST is configured to contact the electronic element 11, it is preferably realized as follows. That is, it is preferable that the gas in contact with the surface of the cooling mist MST that contacts the electronic element 11 moves according to the air current formed by the blower unit. In this case, the cooling mist adhering to the surface of the electronic element is likely to vaporize. Therefore, it becomes easy to quickly absorb heat from the electronic element when the cooling mist vaporizes. Also, the gas in contact with the surface of the cooling mist that contacts the electronic element may be moved so that the cooling mist MST generated in the misting unit 51 moves from the misting unit 51 toward the electronic element 11. That is, an air current may be formed so that at least a part of the cooling mist MST contacts the electronic element 11. In this case, the cooling mist is likely to contact the surface of the electronic element. The gas in contact with the surface of the cooling mist may be exemplified by air or the like.

[0051] [1-2-1. Second Example] A second example of an electronic device equipped with a cooling structure will be described. The second example of the electronic device may be referred to as the electronic device according to the second example. As shown in Figure 5, the electronic device 10C according to the second example has a circuit that converts a DC or AC input into a DC or AC output according to the function of the electronic device. This circuit is referred to as the functional circuit 43A. The DC or AC input is indicated by the arrow IN in Figure 5. The DC or AC output is indicated by the arrow OUT in Figure 5. Figure 5 is a configuration diagram illustrating one embodiment of the electronic device according to the second example.

[0052] (Functional Circuit) The functional circuit 43A is not particularly limited. Examples of functional circuits 43A include circuits that generate large outputs, such as large currents for driving motors or radio waves for transmission at communication base stations. Examples of such circuits include inverter circuits, converter circuits, frequency conversion circuits, regulator circuits, and the like.

[0053] (Functional Circuit Board) In the electronic device 10C according to the second example, a circuit board on which electronic elements are provided on a substrate body has a functional circuit 43A. The circuit board on which electronic elements are provided on a substrate body is sometimes referred to as a functional circuit board 43. Various electronic elements that can be used as electronic elements 11 as described in the first example can be used to form the functional circuit 43A. From the viewpoint of generating a large output, power semiconductors and the like can be exemplified as electronic elements provided on the functional circuit board 43. The structure for attaching the electronic elements to the substrate body may be the same as the element junction 19 described in the first example. The material of the substrate body may be the same as the material of the substrate body 17 described in the first embodiment.

[0054] (Input and Output) The electronic device 10C according to the second example shown in Figure 5 has an input section 44 such as a power supply on the input side. The electronic device 10C also has an output section 45 such as a motor or antenna on the output side. Furthermore, the input section is connected to the input terminal of the functional circuit board 43, and the output section is connected to the output terminal of the functional circuit board 43. However, this is just an example. The electronic device 10C according to the second example only needs to be configured to be able to input to the functional circuit board 43 and to output from the functional circuit board 43. In the case of motor drive, the functional circuit 43A has a converter circuit and an inverter circuit made of power semiconductors. The input section 44 is a DC power supply. The output section 45 is a three-phase AC motor. Furthermore, the wiring 46 on the input side is positive and negative wiring, and the wiring 47 on the output side is three-phase wiring.

[0055] (Cooling Liquid) In the electronic device 10C according to the second example, cooling mist MST is present around the functional circuit 43A. In the example shown in Figure 5, cooling mist MST, which is formed by atomizing the cooling liquid 12 in the atomizing unit, is released around the functional circuit board 43. Thus, in the electronic device 10C, it is possible to have cooling mist MST present around the functional circuit 43A. It is preferable that at least a portion of the cooling mist MST is in contact with the functional circuit 43A. The cooling liquid 12 is supercritical water 21 as described in the first example, so a detailed explanation is omitted. Also, the cooling structure 50, atomizing unit 51 and cooling mist MST are the same as in the first example, so a detailed explanation is omitted. Note that cooling mist MST may be applied to the input unit 44 and output unit 45 so as to remove the heat generated in the input unit 44 and output unit 45.

[0056] In the second example, as in the first example, the cooling structure may be a modified version of the cooling structure shown in the first example.

[0057] [1-2-2. Operation and Effects] According to the electronic device 10C of the second example, since it has a cooling structure 50, the same effects as the electronic device 10 of the first example can be obtained. That is, in the electronic device 10C of the second example, the operation and effects of the cooling structure according to the present invention shown in [1-1-2. Operation and Effects] above occur.

[0058] [2. Cooling System] The cooling system according to the present invention is a system for cooling electronic elements that perform electronic processing. In this specification, the description of the cooling system will continue with the example of a case in which the cooling system cools an electronic device having electronic elements, as shown in Figure 6. Figure 6 is a configuration diagram illustrating a system structure for illustrating one embodiment of a case in which the cooling system cools an electronic device. Figure 6 shows one embodiment in which the electronic device is an information processing device such as a computer.

[0059] (Electronic Devices) Examples of electronic devices 160 cooled by the cooling system 150 according to the present invention include devices of the same type as the electronic device 10, such as information processing devices, which are capable of being provided with the cooling structure described above. The configuration of the electronic device 160 shown in the example in Figure 6 may be the same as that of the electronic device 10 shown in the description of [1. Cooling Structure], except that the configuration of providing the cooling structure 50 within the electronic device 10 shown in the description of [1. Cooling Structure] is omitted. The electronic elements and circuit boards that may be provided in the electronic device 160 cooled by the cooling system 150 may be the same as the electronic elements 11 and circuit boards 15 of the electronic device 10 shown in the description of [1. Cooling Structure]. For this reason, a detailed explanation of the electronic elements and circuit boards that may be provided in the electronic device 160 is omitted. In the electronic device 160 shown in the example in Figure 6, the cooling structure 50 is omitted, but the cooling system 150 and the cooling structure 50 may be used in combination.

[0060] [2-1. Configuration of the Cooling System] The cooling system 150 comprises a cooling chamber 151, a coolant 152, and a misting unit 153. Furthermore, as shown in Figure 6, it is preferable that the cooling system 150 has an air conditioner 155. The air conditioner 155 shown in the example in Figure 6 has an indoor unit 156, an outdoor unit 157, and piping 158. In the air conditioner 155, the piping 158 is connected to the indoor unit 156 and the outdoor unit 157. In the air conditioner 155, the refrigerant circulates between the indoor unit 156 and the outdoor unit 157 by moving through the piping 158. In the indoor unit 156, air from the cooling chamber 151 is taken in, and heat is transferred from the taken-in air to the refrigerant flowing through the piping 158. The refrigerant, having received heat, travels through the piping 158 to the outdoor unit 157, where it receives heat from the refrigerant and releases it to the outside of the cooling chamber 151 (and further to the outside of the outdoor unit 157). This releases the heat from inside the cooling chamber 151 to the outside. The air that has transferred heat in the indoor unit 156 is returned to the cooling chamber 151. In this way, the presence of the air conditioner 155 in the cooling system 150 allows the refrigerant to circulate between the indoor unit 156 and the outdoor unit 157 through the piping 158. This allows the heat inside the cooling chamber 151 to be released to the outside. Furthermore, the presence of the air conditioner 155 in the cooling system 150 promotes the circulation of air inside the cooling chamber 151. Therefore, the cooling mist MST formed in the misting unit 153 can be diffused throughout the entire cooling chamber 151. Also, as will be described later, the cooling mist MST can be collected in the indoor unit 156. In the example shown in Figure 6, the outdoor unit 157 is installed on the outer surface of the wall 151A, but this is just one example, and the outdoor unit 157 may be located away from the cooling chamber 151.

[0061] The coolant 152 in the cooling system is suitable for cooling the electronic element 11 and may be the same as the coolant 12 described in [1. Cooling Structure]. That is, the coolant 152 may be supercritical water 21. Supercritical water 21 is water that has been transitioned from a state at a temperature and pressure exceeding the critical temperature and pressure exceeding the critical pressure to a state at room temperature and pressure. Supercritical water 21 may be the same as the supercritical water described in [1. Cooling Structure]. Therefore, a detailed explanation of the coolant 152 and supercritical water 21 will be omitted in the explanation of the cooling system 150.

[0062] (Cooling Chamber) The cooling chamber 151 comprises a space 154 having a size corresponding to the object to be cooled, and a partition structure that separates the space from the outside. In the example in Figure 6, the partition structure has a wall 151A, a ceiling 151B, and a bottom 151C. The size of the space 154 may be determined according to the object to be placed in the space 154. For example, if an electronic device 160 is placed in the cooling chamber 151, the space 154 is large enough to accommodate at least the electronic device 160. In the example in Figure 6, the space 154 is large enough to accommodate the electronic device 160 and a mist generator as a misting unit 153.

[0063] (Misting Unit) The cooling system 150 has a misting unit 153 as described above. The configuration of the misting unit 153 is not particularly limited as long as it is a configuration that can atomize the coolant 152 into a cooling mist MST. The cooling mist MST may be the same as the cooling mist shown in the description of [1. Cooling Structure] above, so a detailed explanation will be omitted. In the example of the cooling system 150 shown in Figure 6, a mist generator 153A is provided as the misting unit 153. In the mist generator 153A, the cooling mist MST is released from the mist nozzle into the space 154. The structure of the mist generator 153A is preferably a structure that atomizes the coolant by ultrasound, for example, similar to the misting unit 51 shown in the description of [1. Cooling Structure] above. However, this is just one example of the structure of the mist generator 153A. In addition, the structure of the mist generator 153A may also employ a design in which a coolant pressurized to high pressure (for example, about 7 MPa) is pushed out into a low-pressure area from a mist nozzle with a small diameter.

[0064] In the example shown in Figure 5, the mist generator 153A is located inside the space 154. However, if the cooling system 150 is configured to allow cooling mist MST to be released from the mist nozzle into the space 154, then part or all of the mist generator 153A may be located outside the space 154.

[0065] In addition, in the cooling system 150, the coolant 152 may be stored inside the mist generator 153A, or the coolant may be supplied to the mist generator 153A from the outside (not shown). A tank for storing the coolant 152 may be placed in the space 154, and the coolant may be supplied from the tank to the mist generator (not shown).

[0066] [2-2. Operation and Effects] According to the cooling system of the present invention, it is possible to have a predetermined amount or more of cooling mist in the space of the cooling chamber. In the cooling system, the cooling mist can sequentially cool the air and electronic elements inside the electronic device placed in the space, starting from the outside. Also, since electronic devices usually have a part that communicates with the outside (referred to as a communication part), it is possible for the cooling mist to be sent into the inside of the electronic device through the communication part. As a result, the cooling mist can come into contact with the surface of various electronic elements provided in the electronic device. This also cools the electronic elements. In addition, it can be expected that the heat generated in the electronic elements will be absorbed as the cooling mist that comes into contact with the electronic elements vaporizes. Furthermore, if the cooling system has an air conditioner, the vaporized steam (water vapor) of the cooling mist is taken into the indoor unit along with the air. The steam condenses inside the indoor unit 156 of the air conditioner 155. At this time, the heat generated in the cooling chamber 151 is transferred to the refrigerant, and the refrigerant that has had the heat transferred moves to the outdoor unit 157. The heat transferred to the refrigerant is then discharged from the outdoor unit 157. The condensed water is then discharged outside the cooling chamber 151 through the drain (not shown) of the indoor unit 156. Therefore, if the cooling system includes an air conditioner, the cooling mist can be recovered while lowering the temperature inside the cooling chamber.

[0067] The cooling system according to the present invention provides the effects described in [1-1-2. Operation and Effects] of [1. Cooling Structure] above. Specifically, the time during which the electronic device operates normally is extended. Furthermore, with the cooling system according to the present invention, even if droplets of supercritical water 21 adhere to and wet the electronic elements, the impact on the operation of the electronic device is minimal. And because the impact on the operation of the electronic device is minimal even if the electronic elements are wet by droplets of supercritical water 21 adhering to them, it becomes easier to control the generation of cooling mist and temperature. Moreover, with the cooling system according to the present invention, cooling of electronic devices and electronic elements can be achieved at a lower cost compared to when electronic devices having electronic elements or electronic elements are cooled by immersion using supercritical water as the coolant. Furthermore, with the cooling system according to the present invention, it is possible to suppress the need to replace the coolant compared to immersion.

[0068] [3. Cooling Method] The cooling method according to the present invention is a method for cooling an electronic element that performs electronic processing. In this specification, the description of the cooling system will continue, taking as an example the case in which the cooling system cools an electronic device having an electronic element, as shown in Figure 7. Figure 7 is a flowchart illustrating one embodiment of the cooling method for an electronic device. Figure 7 shows one embodiment in which the electronic device is an information processing device such as a computer. The configuration of the electronic device, electronic element, etc. to which the cooling method according to the present invention can be applied is the same as that of the electronic device, electronic element, etc. shown in the description of [1. Cooling Structure], so a detailed explanation will be omitted.

[0069] The cooling method according to the present invention can be specifically realized, for example, by using the cooling structure or cooling system described above.

[0070] The cooling method according to the present invention comprises preparing a cooling mist by atomizing a cooling liquid (reference numeral S1 in Figure 7) and placing the cooling mist around an electronic element (reference numeral S2 in Figure 7). It is expected that the cooling of the electronic element will be promoted as the surrounding area absorbs heat when the cooling mist vaporizes. In the cooling method according to the present invention, it is preferable that at least a portion of the cooling mist comes into contact with the electronic element. When the cooling mist comes into contact with the electronic element, the electronic element is cooled. The cooling liquid is supercritical water. Supercritical water is water that has transitioned from a state under a temperature and pressure exceeding the critical temperature and critical pressure to a state under normal temperature and normal pressure. The cooling liquid and supercritical water may be the same as the cooling liquid and supercritical water described in the description of [1. Cooling Structure]. Therefore, a detailed description of the cooling liquid and supercritical water will be omitted in the description of the cooling method.

[0071] According to the cooling method of the present invention, the same actions and effects as those described in [1-1-2. Action and Effects] of the cooling structure can be obtained.

[0072] 10: Electronic equipment 11: Electronic element 12: Cooling liquid 14: External equipment 15: Circuit board 50: Cooling structure 51: Misting unit 21: Supercritical water 100: Pressure boosting unit 110: Temperature boosting unit 120: Piping MST: Cooling mist

Claims

1. A cooling structure for cooling an electronic element that performs electronic processing, comprising: a cooling liquid for cooling the electronic element, which is water that has been transitioned from a state under a temperature and pressure exceeding a critical temperature and pressure to a state under normal temperature and normal pressure; and a misting unit that generates a cooling mist by atomizing the cooling liquid.

2. A cooling structure according to claim 1, wherein at least a portion of the cooling mist is configured to come into contact with the electronic element.

3. A cooling structure according to claim 2, comprising a blower that forms an airflow.

4. An electronic device comprising the cooling structure described in any one of claims 1 to 3, and the electronic element that performs electronic processing.

5. A cooling system for cooling an electronic element that performs electronic processing, comprising: a cooling chamber having a space for arranging the electronic element; a cooling liquid for cooling the electronic element, which is water that has been transitioned from a state under a temperature and pressure exceeding a critical temperature and a pressure exceeding a critical pressure to a state under normal temperature and normal pressure; and a misting unit that generates a cooling mist by atomizing the cooling liquid.

6. A method for cooling an electronic element that performs electronic processing, comprising cooling the electronic element with a cooling mist formed by atomizing a cooling liquid, wherein the cooling liquid is water that has been transitioned from a state under a temperature and pressure exceeding a critical temperature and pressure exceeding a critical pressure to a state under normal temperature and normal pressure.

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